| Author | Message | ||
| Brian Elfert
Rating: |
I'm really torn between a 6V92 and a 8V92. The buses I'm most interested in are the 96A3, 102A3, or 102C3. The 8V92 will be more expensive I know. If I get a 6V92, will I regret it the first time I start climbing the grades on I80 through Wyoming, Salt Lake City, and Nevada? Does anyone have real world examples of MPG in a 6V92 or 8V92 at 65 MPH? What about 70 MPH? Will an 8V92 cost more for overhaul or replacement? | ||
| Bryce Gaston (Busted_knuckle)
Rating: N/A |
Brian I truely believe a 6V92 will do fine! It was what Greyhound used as it's workhorse until the 50 & 60 series engine came along! Yes 8V92 has more power, and uses more fuel, yes 8V92 has 2 more cylinders which means more parts & machining so yes 8V92 will cost some more to rebuild, although not extremely. FWIW! | ||
| Brian Elfert
Rating: N/A |
Sure, Greyhound used 6V92s, but they used them to keep fuel, rebuilding, and maintainence costs down. Extra costs add up with 100s or 1000s of buses on the road. Greyhound can simply add more time for routes that go up steep grades. Passengers won't care as long as the bus stays on schedule. Of course, I too can add more time for grades, but I also know that I had a choice of engine. Greyhound drivers don't have a choice. Brian Elfert | ||
| JR Rating: N/A |
I have real world knowledge of MPG with a 6V92TA DD1 and Allison HT748R all mounted in an 87 MC9. It gets 6 plus a little when crusing at 65 or 68. I could not go 70 MPH last year, but now I can. Made some mods to the limiting parameters. Still 6 MPG is what I got while on the inerstate. And if you drove at the same speeds I do, with an 8V92TA automatic, you'll get about 6 too. Romp it to the floor in the hills and you'll see 4 MPG or less. If concerned about fuel use, go with a 50 Series. They are best, but don't have any more power than a good 6V92TA. 60S is only going to be found in high priced shells. | ||
| FAST FRED Rating: N/A |
"will I regret it the first time I start climbing the grades on I80 through Wyoming, Salt Lake City, and Nevada?" A coach will be dragging 100 lbs for each HP it has up the hills , changing that to 130lbs per hp doesn't change the road speed by very much. The hassle with EVERY DD is that under about 60% of rated (what its set up for) power , they become very inefficent. That's why DD builds them in 1.2,3,4,6,8,12 and 16 cylinder versions. If you pick a setup that can climb hills like a deadheading truck, you will be stuck with crappy fuel milage the OTHER 99.9% of the trip. Does climbing at 40 instead of 50 hold real problems for you? FAST FRED | ||
| Bill K Rating: N/A |
I don't know how many of hunder thousand of miles you are going to travel that a little fuel mileage will make. Also if you keep you foot out of it there should not be that much difference, but when you need the power you will have it with the 8v. My self I would weather have it and not need it, but when I do it's there. Far as a rebuild, a good 8v92 should go 500,000 mile plus. How many rebuilds are you going to need. My vote is for the 8v92 or 60series. IT does cost a lot to up size later on. | ||
| Brian Elfert
Rating: N/A |
Are there any coaches out there with a Series 50 in them for sale? I've never seen one in a coach for sale except a MC-9 on Ebay that was repowered. I think I'll stick with the 6V92 unless I can find a Series 50 or get an exceptional deal on a 8V92. Brian Elfert | ||
| Jon W. Rating: N/A |
I have driven an 8V92 in a 41,000 lb. Prevost towing a 4000 lb. car over 200,000 miles. Lifetime fuel consumption is 5.6 MPG. I recorded every gallon that ever went in the coach and the number is skewed a little by the fuel consumed by the genset which I can't separate. If it helps the genset ran 1200 hours during that same time. You only pay (in fuel) for the HP you use. There is nothing better than having the power to pass when necessary or pull a steep hill. It makes a trip a lot more relaxing. | ||
| sylverstone (Sylverstone_pd4501864)
Rating: N/A |
brian: having just finished a coast to coast run in a heavily loaded scenicruiser with an 8v71n and a spicer 4 speed in it, maybe my experience can be of help? my tranny may be shot. i know my shift linkage is, as the bus pops out of 3rd on downgrades. we were loaded really heavy, that plus a full tank, etc put us into the "very heavy" category. as i headed up i-5 to i-90 i was heard to comment "i love this bus, but why would anyone put a 4 speed in it?" i would have been much much happier if i could have had another gear between 1st and second, and three beteeen second and 4th. this was followed, upon contact with foothills, with "okay, keep it on the governor in 3rd, should be fine" ... nope. anything over 3% required second gear, which on the governor was 22mph according to the gps. having been taught to come down it in the gear you came up it in, i came down it in second. across the flats she'd pull 70 in 4th without a problem. coming up the continental divide i got tangled up in slow right lane traffic, and ended up climbing all the way to the top in first gear, as she couldn't pull second from that low of an rpm. a 10 mph crawl up a mountain is a really pretty view, although it drags a bit  when i saw the other side of that, i went down it in first, because by then i had popped out of second once, and slower is better, period halfway down, popped out of first. stomped the clutch, slapped the trottle, and slipped it back into first. happened 3 times on the way down. if i missed getting it back in, the brakes would stop us from 35 for sure (tested) but above that i wasn't sure, so i was being very very careful. all in all a fun trip dropped in at us coach and let luke check out my cruiser, spent a few days, and headed to pennsylvania... anyway, the adage is, time is money. but is it? 6v-92 = 552 cid 300 HP at 2100 RPM 8v-71 = 568 cid 280 HP at 2100 RPM 8v-92 = 736 cid 400 HP at 2100 RPM looks like 20 more hp than my 8v-71, or 120 more, depending on which motor you go with. my cruiser weighs about 25k with a full tank, and no seats or interior in it, and performs like a champ with the 8v-71 and the 4 speed in it. it sucks when it's havily loaded though. (50k+) the 6v-92 would be awfully small in mine, but with the right transmission it would be fine. your coach is going to have a much more modern drivetrain than mine will, as mine is 50 years old at this point. the 8v-92 turbo aftercooled is what everyone seems to suggest for me, but as i need to replace my transmission linkage, and intend on putting serious miles on this rig, i'm going with a 14L series 60 and a 10 speed eaton autoshift. all the ones you're looking at weigh about 27k, i'd call it 23 without the seats and package racks. if the 10 speed eaton would work with the 8v-71 i'd be fine with my engine, but it's an electronic transmission, and would work best with the series 60, and would get much better mileage doing so, and i'll be putting 20-30k a year on this rig, so the series 60 makes sense for me, especially in light of the big mountains we have over here. if your going to do under 10k miles a year, i wouldn't stress the extra fuel useage of the 8v-92. if your rig is going to be light (35k or less) then i wouldn't bother with the 8v-92. the 8v-92 is the "easy upgrade" for my rig, and the cruiser is considered a heavyweight i think... (30k off the assembly line) within reason, you can run just about anything. given enough transmission gears and enough rear end gearing you could run a 4v-92ta ... but the smaller the engine the harder it has to work. tourque does work, horsepower does it faster. i, personally, wouldn't run a 71 or 92 series motor if i had to put it in, either, but i have a plasma cutter and a tig. "regret" isn't a word i would use. it's a bus, it's a labor of love. you can cover 100 miles in 2 hours if it'll pull mountains at 50. it only takes 4 hours at 25. the extra 2 hours is what you pay for the gas mileage, assuming the 6v-92 won't pull the grade, which isn't necessarily true. (it will) 40 ft long 96 / 102 in wide Approx: 11 ft high Wheelbase: 285 in Approx Weight: 27,600 lb seems to me the decision is pretty easy... i'd go with the 102<something> if you're tall or wide, as the extra 6" matters in that case, but my bus is 96 wide and i'm fine with it. all things being equal, the 96" wide bus will probably cost you less, as it's not as "modern" and will get better mileage, as it punches a bit smaller hole in the air, if you assume the aerodynamics are otherwise the same, which from the pics i saw they appear to be. i've heard people throw around formulae like: "5 gallons per 100 horses, per hour." "71 series = 1 gallon per cylinder per hour." and so on. no idea on accuracy, and i think that's in a marine environment, but what it tells me is that there is a math involved in all this, that works out to something like "with the 8v-92 you will, worst case, get something like 20% worse fuel economy, but only if you use the extra ponies it will provide over the 6v-92" you're talking an extra 100 horses. according to mcicoach.com, so DDC 6V-92TA 300 HP at 2100 RPM DDC 8V-71 280 HP at 2100 RPM DDC 8V-92TA 400 HP at 2100 RPM compared to my rig, i would say the 6v-92 will do ya fine, and cost less to operate, but be prepared to slow down on mountain climbing (rockies and cascades, the apps aren't real mountains) if you're going to build it real heavy (figure your seats weigh 5k, so call it 35-40k total weight when finished) then go for the 8v-92, since the fuel economy won't be much worse unless you're doing over 55 or want to climb hills in a hurry. i think purchase price will be the deciding factor, but if it were me i'd be after the 8v-92ta and i'd be looking to put jake brakes on it, and real guages in it, (oil temp, trans temp, axle temp, pyros) almost immediately. but that's me -dd | ||
| R.J.(Bob) Evans (Bobofthenorth)
Rating: N/A |
In the 2 years since we bought our 1981 Prevost w/8-92 & 10 spd Roadranger we have put 22,976 miles on it. We have averaged 6.25 MPG to the Canuck gallon (5.19 per US gal) all in - including gennie consumption. That includes absolutely every gallon of fuel that has gone in from the day I picked the coach up. Those miles include crossing Roger's Pass 5 or 6 times and Monida Pass a couple of times. We towed a Nissan micro-truck for part of the time, my Exploder trucklet some of the time & a competition ski-boat some of the time. Very few of those miles (less than 1000) would have been bus-only miles. | ||
| Pete/RTS Daytona (Pete_rtsdaytona)
Rating: N/A |
Brian see--> http://www.ghgregistries.ca/registry/out/C1688-01DEC95-RPT.PDF go to appendix I Interesting data (Fuel consumption / engine type) at 1800 RPM's (most) and 60% loading for many engine sizes and types - Imperial gallons/hour and stationary motors - but still very helpful series 50/60 vs 6v92/8v92 included Pete RTS/Daytona | ||
| Dale Waller (Happycampersrus)
Rating: N/A |
A 6v92 can run 350hp with an injector swap. That would be about all the grunt you will ever need. As Fast Fred points out couple of extra cylinders won't change the speed much, but they will use fuel. Also if you decide on a 8V92 make sure it is a factory install! Several have upgraded from a 6v to 8v just to have cooling problems. My 6V92 V730 gets right at 8mpg with 9290 injectors. FWIW, Dale | ||
| Brian Elfert
Rating: N/A |
Dale, I'm guessing you have a transit since you have the V730 tranny? Isn't a transit going to get better MPG due to lower wind resistance and lower weight? I am only planning on buying a coach that came factory with an 8V92 if I go that direction. Brian Elfert | ||
| Dale Waller (Happycampersrus)
Rating: N/A |
Brian, Yes, I have the fastest Fishbowl around. It's a 35 foot with highway gears. 74mph is all I can do, but I can get there quik. Wanna Drag for pinks?? I ran into heating problems when I swaped out the 6v71 I had to have a radiator from a 6v92. I am a Heavy Equipment Mechanic by trade, so I enjoyed the repower. That's why I suggested getting a factory 8V92. This was a starter bus for me to learn from. As I get closer to retiring I will get a MCI or a Prevost to take my time and convert to hopefully full time in. Dale | ||
| Gary Carter Rating: N/A |
We have a 45,000 pound Newell with an 8V92TA DDEC. Keep a running spread sheet and for the past 20,000 miles have averaged 6.48 mpg. I installed a Horton fan clutch last summer, but am not ready to give mpg yet. Should have a better idea by July. We got slightly better mpg coming to Yuma this past fall, but battled 40+ mph headwinds most of the way. BTW I drive about 63mph which is 1700 rpm. The best milage on the 92 series is 1600 - 1700 rpm. | ||
| Brian Elfert
Rating: N/A |
The gallons per hour study of well drilling equipment is interesting, but only 1 6V92 and 1 8V92 were included. It is hard to know how accurate the numbers are when there is only one of a particular engine in a study. The Series 50 is only marginally more fuel efficient than the 6V92 per this study. It shows the 8V92 as consuming 50% more fuel than a 6V92 which seems hard to believe. I would still like to find a bus for sale with a Series 50. It is probably the ideal mix of fuel mileage, HP, and long term maintainence costs. Brian Elfert | ||
| Bryce Gaston (Busted_knuckle)
Rating: N/A |
Brian there is a Neoplan in Colorado on EBAY with a 50 in it right now! | ||
| Bryce Gaston (Busted_knuckle)
Rating: N/A |
TRANSIT BUS 86 NEOPLAN Item number: 4616288971 | ||
| Brian Elfert
Rating: N/A |
I should clarify that I would like to find a Series 50 in a coach, not a transit. I can find plenty of Series 50 engines in transits. Until I read about the Greyhound MC12s with Series 50, I didn't know MCI had ever put a Series 50 in a coach from the factory. I have never seen a coach with factory Series 50 advertised for sale in the few months I have been looking. Bryce, the same guy who is selling the transit bus on Ebay also has a bunch of other buses for sale. Some of them seem pretty overpriced like an MC9 for $25,000. That MC9 should be like showroom new for that much money. Brian Elfert | ||
| john w. roan (Chessie4905)
Rating: N/A |
One thing to consider is that jake brakes on an 8V vs. 6V are going to be better in a heavy coach in the mountains. You could derate the 8V for slightly better mpg.and longer life. The better MPG from derating is an arguable point by some as particular situations will vary.Just more food for thought to add more confusion. Personally, I'd go with the 8V92. | ||
| Bryce Gaston (Busted_knuckle)
Rating: N/A |
Brian yes I know he's as high as Pike's Peak in what he'd like to get out of themand I was just pointing out that it was there! To be honest I'm thinking about it as a repower donor! Just passing on what I saw. | ||
| Steve75mc5b Rating: N/A |
Hello, I would like to add my 2cents worth. Fuel mileage has alot to do with the amount of cetane. The national average is 42.5 cetane.Premium is classified as 47 cetane#. The higher the cetane, the better the fuel mileage. For thoes who are wondering what cetane is, 2-ETHYL HEXEL NITRATE. 5600PPM Improver is what you need to look for. There is a company in the Indpls, In. area that sells that product. Good luck! Steve75MC5B | ||
| FAST FRED Rating: N/A |
i've heard people throw around formulae like: "5 gallons per 100 horses, per hour." "71 series = 1 gallon per cylinder per hour." About the best you will get from a DD is 16 hp / gal The one gal per cylinder is a rule of thumb for selecting an engine for an application. One gal per cylinder is a good minimum light load that the engine will survive with a long time. Near 2 gal per cylinder is only for short duration , a winch or similar , not a pump or generator. FAST FRED | ||
| sylverstone (Sylverstone_pd4501864)
Rating: N/A |
hey fred, read a lot of your posts in the short time i've been here.. and if i haven't said thanks yet, thanks. i appreciate it -dd | ||
| Tom Caffrey (Pvcces)
Rating: N/A |
Steve75mc5b, I have a completely different idea of what cetane does for an engine than you do. The main difference in what you're talking about is that I believe after cetane is high enough to give good starting, it doesn't do any good to raise it further. The information I have is that it lowers the ignition temperature of the fuel; what you want is a fuel that ignites in the right part of the stroke, early in the injection. If temperatures are too low for good ignition, it causes a kind of hang fire condition and makes for really loud fuel detonations. This is what makes light duty diesels suffer so much if they are run too fast before they warm up enough. For what it's worth. Tom Caffrey PD4106-2576 Suncatcher Ketchikan, Alaska | ||
| Dale Waller (Happycampersrus)
Rating: N/A |
Cetane is the rating system for diesel fuel ignition properties. The higher the number the easier the fuel ignites. It won't have much if any impact on fuel milage as long as the rating is adequate enough to ignite at the correct time as Tom states. If the rating is too high (Mid 50s and above IIRC)it will cause problems by igniting too soon. Alot of noise if the engine starts at all. |
